Screen printing apparatus



March 1l, 1952 w. M. REEMELIN ETAL SCREEN PRINTING APPARATUS 5Sheets-Sheet l Filed Sept. 16, 1946 AT TO R NEY5 5 Sheets-Sheet 2 W. M.REEMELIN ET AL SCREEN PRINTING APPARATUS Wl l www fw; ATTORNEYS March11, 1952 Filed sept. 16, 194e March 11, 1952 wl M, REEMELlN ET A L2,588,878

SCREEN PRINTING APPARATUS Filed sept. 1s, 1946 SASheetS-Sheet 3 L#79.175,I f

/r\\ //l\ INVENTORI WALLACE M. REEMELIN BY ROGER W. OLMSTED AT TOR NEYMarch l1, 1952 w.Y MREEMELIN ETAL SCREEN PRINTING APPARATUS Filed sept.16, 194e 5-Sheets-Sheet 4 www INVENTORS. WALLACE M. REEMELIN ATTORNEYSMarch 11, 1952 w. M. REEMELIN ETAL SCREEN PRINTING 'APPARATUS "5'sheets-sheet 5 Filed' sept. 16,- 194e )37am M W7 ATTORNNS PafenteclMar. 11, 1952 SCREEN PRINTING APPARATUS Wallace M. Reemelin, Berkeley,and Roger W. Olmsted, San Francisco, Calif., assgnors to Foster andKleiser Company, San Francisco,

Calif.

Application September 1.6, 1946, Serial No. 697,294

2 Claims.

This invention relates to screen printing apparatus of the type used forprinting by the silk screen process, and has for one of its objects theprovision of apparatus for eieeting a more rapid printing thanheretofore, particularly where relatively large sheets are printed, suchas each of,`

the'sheets used on large bill boards to make up u the large poster.

lAnother object of the invention is the provision of screen printingapparatus that facilitates the positioning and removal of the sheetsthat.l

have been imprinted as well as the printing, and with the minimum amountof labor:

A still further object of the invention is the provision of screenprinting apparatus that is arranged and adapted to enable one workman,

to position and remove the relatively long sheets from the elongatedrectangular printing base of the apparatus from one of thelongitudinally extending sides of such base while a single workman atone of the ends of the apparatus actuates the squeegee in one directionor the other in direction longitudinally of the base and printing frame,the latter generally corresponding in shape with the printing base.

In screen printing apparatus, the screen' cr `printing frame andprinting base therebelow are usually oblong in plan view and arepositioned horizontally. The frame, heretofore, has generally beenhinged along one of its longitudinally extending edges to the base,andtherefore the paper or material to be printed must be positioned andremoved from some one or more of the three remaining sides when theprinting frame is swung open. Inserting or removing the paper from theone longitudinally extending side that,

is opposite the printing frame hinges is awkward" where long sheets ofpaper are being printed inasmuch as two operators must inserttheelongated sheets, one being at either end of the latter, and theoperator that positions the sheets must work from the same side of theapparatus to adjust the sheets so they will register correctly with thescreen or previously printed color. If the sheets are inserted andremoved from opposite ends of the frame, it is obvious that the time forremoval is longer than were the sheets removed from one side, and alsomuch greater space is required.

Also, heretofore it has beentcustomary in larger screen printingapparatus to require two operators to operate the squeegee, the latterbeing L drawn from end to end of the screen frame. One operator is ateach side of the frame. The squeegee is removed from the `frameaftereach printing to enable the frame to swing open,

With the present invention, one man at one side of the apparatuspositions and removes the paper, and the paper is removed from the sideof the frame opposite the operator. Also, only one man at one end of theapparatus is required to operate the squeegee and the squeegee remainsin position on the printing frame after each operation. In addition tothese advantages, the printing frame and printing base are movedrelative to each other to and from closed position by means of fluidpressure, which merely requires the opening and closing of a valve,whereas in prior apparatus, the operators have been required to manuallyswing the frame away from the printingwbase. When it is considered thatthe printing frame must be of rugged construction and on large apparatusis about four feet wide and twelve feet long for printing 34 by 84 inchsheets,

'it is manifest that the manual swinging of the frame takes time andeffort even though each such frame is usually counterbalanced.

Other objects and advantages will appear in the description and in thedrawings.

In the drawings:

Fig. l is a side elevational view showing the apparatus with theprinting frame and printing base together and the squeegee about midwaybetween the ends of the printing frame.. A portion of the frame isbroken away adjacent one end to show structure otherwise concealed.

Fig. 2 is a plan view of the printing base only, with the supportingposts and braces indicated in dash lines.

- Fig. 3 is a side elevational view of the base of Fig. 2, one of thetelescoping posts being broken vaway and indicated in section.

Fig. fl is an enlarged fragmentary sectional view takenalong the line4-4 of Fig. 2.

Fig. 5 is aschematic View of the fluid pressure `system connected iwiththe extensible telescopic j supports for the printing base.

.. v1i'ig."6 is an enlarged part elevational and part sectional view ofone of several identical elevating ,means for automatically elevatingthe squeegee in .Section- Fig. 9 is an enlarged sectional View takenalong line 9-9 of Fig. 8.

Fig. 10 is an enlarged sectional view along line Ill-Iii of Fig. 8. iFig. 1l is an enlarged, part sectional and part elevational view throughone of the collapsibie pneumatically actuated supports for the baseframe.

Fig. 12 is an enlarged, fragmentary sectional view of part of thesqueegee and printing frame.

Fig. i3 is an enlarged View as seen from line I3-I3 of Fig. 12.

Fig. 14 is a diagrammatic, simplied plan view of the printing apparatusand a portion of the conveyor belt.

In detail, a rigid, horizontal printing frame I is supported on legs 2elevated a substantial distance above the floor 3. This frame is usuallyoblong in plan View, and in the present invention a platform 4 is at oneend of the frame and at about the same elevel. Stairs or a ladder 5 maybe provided for the squeegee operator' I5 toY climb to and descend fromthe platform. Usually the platform has an extension 1 along oneV side ofthe f frame for said operator to walk from one end of the frame Vto theother, and a railing 8 may also be provided for safety reasons.

In Fig. 14 a diagrammatic plan view' of the arrangementY is shown, andin said View it will he seen that thestack or supply 9` of paperv to beprinted is at the end of the printing frame op,-

pcsite platform 4, while a take-ofiv roller IU? is along onelongitudinally extendingl edge off the" A conveyor I'I extends awayfrom. the

frame. tafe-oii' roller for carrying the printed sheets through or undera drier that Vdoes not form a part of this invention and that is notshown. The operator that positions the sheet to be printed and thatremoves it after the printing operation, stands at about position I2. Itis to be understood that the take-ofi' roller I0 and conveyor II are allat about the level' of the printing frame, as will later be describedmore in detail.`

The printing base, or what would, in conventional' screen printingconstitute the stationary table, is indicated at I3, and is below theprinting frame.

ThisY base i3 is supported at its four corners on telescopicallyextensible and collapsible tubular legs, generally designated I4, whichllegs are extended by pneumatic pressure to different levels as willlater be explained. In Fig. l the full line position of the printinglbase indicates its uppermost position, while the dash line positionIii` indicates the intermediate working; position being somewhere around35 or 40 inches from theV floor. There is a third or lowermost position(Fig. 3) in Y which the legs are fully collapsed to their limit,

and in which the. printing base is about half way' between position, I5and the floor` When in this latter position there is adequate spacebetween the printing base and the printing frame to facilitate work byan operator on the lower side of the screen or stencil attached thereto,or any" other work that requires, more Working space than is permittedby the space between position I5 in Fig. 1 and the full line position ofthe printing frame.

The legs I4 each comprises an outer cylinderA Secured to the upper endof said cylinder said head being centrally apertured for reciprocationofy intermediate cylinder therethrough, the latter having a piston orcup-washer 21 secured to its lower end and reciprocable in outercylinder 2t. The head 25` mayl function as a stop for the plunger' 21.

The head 25 is also formed with a passageway 28 connecting with airpressure line 29 at one end and communicating with the inner lower endportion of intermediate cylinder 2 I when the latter is iin extendedposition, thus enabling air pressure entering; said portion to extendthe inner cylinder Inner cylinder 22 is provided with a head at its'uppery end on which. the printing base I3 is supported,A while the lowerend is provided with a piston or cup-washer 30 that is reciprocable inintermediate cylinder 2|. The said cylinder 22 is also reciprocablethrough a head 3| that is in the upper end of the intermediate cylinder2 I.

As seen in Fig. 5', air lines 24' communicate between the iower ends ofeach of the outer cylinders` 20 and a common air line 35 that in turnconnects with a source 36 of air under pressure. A manualor footoperated valve 31 in said air line 35 connects the outer cylinders withsaid source 36 when in the position indicated in Fig. 5 or when thevalve is' rotated a quarter turn the outer cylinders may exhaust to theatmosphere for collapsing under the weight of' theprinting base to theposition shown in Fig. 3.

Air lines 29 `communicate with the space betweentllel pistons 21', 3Dand a common air line 38 that in turn.v connects with said source 35. Afoot or' manually actuatable valve 33 in line 31 is similar tovalve 31and when in the position indicated in Fig. 5v admits air under pressureto below piston 30 for maintaining they cylinder 22 expanded as seen inFig. Il. A quarter turn of thevalve 39. will open the interior ofcylinder 2| to" the atmosphere permitting the inner cylinder 22r todescend to collapsed position within the intermediate cylinder 2l.

In actual practice, when the apparatus is ready for printing, the valve31 is open, thus elevating the printing base to position I5 (Fig. 1) andthe valve remains open'. The operator then positions a sheet-of paper inproper position on the printing base and opens the valve 39, whereuponthe base is elevated, bringing the sheet against the screen' or stencilcarried by the latter. The squeegee is then moved across the screen toforce the paint. through the latter and onto the sheet that' is on theprinting base, after which the valve 39 is moved a quarter turn so as toclose the line leading to the source of air 36, and open to exhaust thelines 29 leading from the valve tothe lower ends of the intermediatecylinders,

.whereupon the printing frame carrying the printed sheet will be loweredto position I5 (Fig. 1)'. vThe operator then merely lifts the sheet 4i!(Fig. 7a) onto the rapidly rotating take-01T roller III that in turndeposits the printed sheet on conveyor I-I for carrying below infra-reddrying lamps 4 I. The conveyor II and roller Iii may be driven by anysuitable source of power connected with a belt or chain 42 that in turnextends over a pulley VI3 supporting one end of conveyor Il, while asuitable belt 44 may connect the pulley shaft 45 with roller Ill'.

The printing base I3' has upstanding members 46 projecting from itsupper side along two adjacent edges of the base for positioning each5h98@ t0 he Printed, in @he .Same position on said base in or to insureproper register. These members must be retractable or movable downwardlywhen the base is moved against the printing screen to permit theprinting step. Fig.- 4 shows the yieldable support for each member 46.

Each member (which is preferably rectangular in horizontalcross-sectional contour (Fig. 2) extends through a correspondinglyshaped opening in said base. A shoulder 41 (Fig. 4) on each memberlimits the upward movement thereof, and expansion springs 48 connect thelower ends of said members (below the upper surface of base I3) withsaid base. Thus, as soon as the upwardly projecting ends of the members46 engage the printing frame, the springs 48 will expand to permit saidends to come flush with the lower side of the frame whereby the sheet onsaid base will be tight against the printing screen or stenciltherebelow. 'Ihe springs will cause the members 46 to automaticallyreturn to the' position shown in Fig. 4 when the printing base islowered.

In order to prevent objectionable shock, expanded coil springs 49 arecarried by the printing frame and depend therefrom (Fig. 1). Thesesprings are engaged by brackets 50 (Fig. 4) carried by base I3 justbefore the printing base reaches the uppermost end of its movement, thuscushioning the blow that would otherwise result from engagement betweenthe printing frame and base when the latter is moved to printingposition. An upward projection `I on each bracket 50 (Fig. 4) is adaptedto enter the lower end of each spring 49 when said base frame is inelevated printing position. Other similar springs 52 carried by theintermediate cylinders 2| function for the same purpose.

The printing frame, generally designated I, comprises marginal framemembers 54 (Figs. 8, lo) that may be angle iron strips arrangedwith oneof their sides 55 vertical and their other sides 56 horizontal andextending outwardly relative to the center of the frame. These stripsare arranged to provide an oblong or rectangular frame (Fig. 7).

The screen 58 is secured at its marginal portion against the undersideof the sides 56 of angle strips 5e by strips 59 that in lturn aresecured to the inwardly extending` sides 6I) (Fig. of an outer frameformed of angle strips 6I. The other sides 62 of angle strips 6I extendvertically across the outer sides of angle Strips 54 and project abovethe level of the upper edges of the sides 55 of the latter. `An outerframe 63 en closes strips 6I and carries the later.

0 The lower sides 60 of angle strips 6I terminate below the lower sides56 of angle strips 54 along lines spaced outwardly of the inner sides ofthe latter strips, thus permitting the printing lbase to pass into thespace defined by the free inner edges of lower sides 66 of strips 64 andinto close engagement with screen 58.

The lower sides 56 of angle strips-54 may be apertured at spaced pointsfor passing elements 55 on strips 59 therethrough. These elements areeach formed with a horizontal through opening for a wedge 66 (Fig. 12)that functions to tighten strip 59 against screen 58. Upon knocking outthe wedges the screen is readily removed for replacement.

The upper edges of angle strips 6I (Figs. 8, 10) that extend along thelongitudinally extending sides of the screen frame, form tracks forflanged wheels 'I6 of the squeegee.

The squeegee itself is generallyl designated 69A y and comprises a crossmember 'II that extends between wheels 'IIJ and over screen 58. Thiscross member carries the flexible blade 'I2 (Fig. 9) that engages thescreen 58 and that functions to scrape the painting medium over thescreen from end to end of the latter during each printing operation. Theblade or scraper portion of 4the squeegee is vertically adjustabletoward and away from the screen by means of a screw 'I3 -that threadedlyextends through a nut 'I4 secured to a transversely extending metalstrap 'I5 that is centrally between the ends of said cross member, 1I.The lower end of screw 'I3 is rotatably secured to a vertically slidingblade holder T6 (Fig. 9) that receives the upper edge of the ilexibleblade '12. A spring 'I8 reacts between the holder 'I6 and a washer 'I9against nut 14 to yieldably hold the holderl6 in expanded position,while a predetermined pressure on the squeege will cause the latter tomove upwardly compressing the spring 18. By turning the screw 'I3 theblade holder may be moved in one direction or the other axially of saidcrew until the desired position for best work is obtained.

A relatively long handle 'I9 is secured to the squeegee and projectsslantingly upwardly therefrom in the direction of the platform 4. andover the latter so that the operator 6 on said platform can move thesqueegee from one end of the printing screen to the other upon walkingback and forth on the platform.

The handle 79 is generally of U-shape with the free ends connected tothe ends of the squeegee as best indicated in Fig. 8, while the closedend of the U is adapted to be grasped by the hands of the operator asseen in Fig. 1.

At the same points where the free ends of the U-shaDed handle i9 connectwith the squeegee are laterally projecting arms 8i (Fig. l2) that extendlaterally from the squeegee in the same direction as arrn '19. Each ofthese arms carries a roller 82 at its outer end, and each such roller isadapted to -engagethe upper edge of the side of the angle strips 54 thatextend parallel with the angle strips supporting the squeegee (Fig. 13).A brace 63 extends upwardly from the outer end of each arm 3 to the sidemembers of arm 'i9 to brace the wheels 532.

The provision of said wheels enables the operator to elevate thesqueegee, if he so desires, by pivoting the squeegee on the wheels uponmoving the handle 'i9 downwardly.

At the opposite ends of the screen frame are portions 85, 86 that areoutwardly bey-ond the printing portion of the screen. The paintingmedium on the screen is deposited on one or the other of these endportions according to the position of the squeegee. These portions maybe imperforate or may be blocked off by extensions at the ends of theprintingr base or in any other suitable manner. The important thing isthat the paint is held on said portions against going through thescreen. or frame when the printing base is moved away from the screenframe or vice versa. Such portions are employed in practically allconventional screen printing apparatus.

The present invention provides means for automatically elevating thesdueegee over the paint after the latter has been drawn across thescreen in one direction and for then causing the sdueegee to re-engagethe paint upon reversing the directional movement of the squeegee fordrawing the paint back across the screen.

The above means comprises a pair of oppo-sedly positioned verticalplates @il (Figs. 1, (i, 7) posispaced, vertical, parallel links M.

tioned adjacent the vertical sides 6-2 of the angle strips 6I: on whichwheels lil of the squeeg'ee are supported. There one pair at each of thecorresponding ends of the angle strips 6|-, and each of said platesextends through the upper flange 9| (Fig. 6)' of the side frame membersE3'. The plates 90' are horizontally elongated, and the end of eachplate nearest a central point intermediate the ends and frame members 63is connected to said frame' members' by a pair of horizontally Saidlinks 9A are pivotally connected at their upper ends to said end. ofeach plate 98 by pivots 95, while the lower ends' of said links are'connected with frame members 63` by pivots 95. A spring 9)? yieldablyholds each plate 90 in elevated position against one end 98 of the slotin flange 9| said end being most remote from said links, or adjacent theouter ends of the frame members 63. The upper edge of each plate isparallel with and above the level upper edge of the side 62 of eachangle strip di on which the wheels 'it' are supported. The adjacent endsof the pair of plates at opposite ends of each of said angie stripsextend slantngly upwardly as at 93 to said upper edge' of each plate,and. the tracks' formed by said sides 62 of said angle strips' extendslantingly upwardly at points 99 adjacent the outer ends of said platesso that the wheels l' of the Squeegee in moving from thev screen over'said portions t5 or 36 at the :s:

ends of the screen, will move upwardly onto the upper edges |05) ofplates 9d' and then onto the elevated ends lill of sides Thus the bladeof the squeegee. will pass upwardly over the supply of pair'it` it hasdrawn over the screen' as soon as the paint is deposited on either ofsaid positions 85, or 86.

The plates Si! are' held against the ends 9% oi the slots in ilanges 9!against downward movement when the wheels 10 run upwardly onto said yplates over inclined edges 93. However, upon movement of the squeegee,as soon as the wheels 'l0 run downwardly over the edges 93 of sides 62onto the ends of plates 9e that are remote from links 94, the plates 9!!will swing downwardly to position the' squeegee blade alongside thepaint that is on either portion 85, or 86 as the case may be, fordrawing said paint across the screen 58 upon continuing the movement insaid reverse movement. The operator may, of course, tilt the squeegeecarriage at any time about rollers 82 for elevating and lowering thesqueegee blade,

'and the sdueeg'ee can be rolled on said rollers in said tilted positionas well.

In operation in printing a conventional job on sheets that are, say 34 X84 inches in size, the operator at position I2 (Fig. 14) may positionthe printing base in the dash line position I5 shown in Fig.k 1. Thestencil is placed on the printing base, being properly positioned by theprojections 46 that are along the sides adjacent the feed device 9 andthe take-oil roller ID. The operator then actuates valve 39 forelevating the printing base to a position against the underside of thescreen 5B. The operator 6 then draws the paint over the upper side ofthe screen by means of the squeegee 69, thereby causing the stencil tostick to the frame. A sheet of any kind may be between the printing baseand the stencil to keep the base clean during the operation of adheringthe stencil to the screen.

In some 'instances parts of the stencil may have to be adhered by hand,or removed, after the. rst operation above described, and in suchinstances the operator l2 may lower the printing base to fully depressedposition (Fig. 3)'v and do the necessary workV on the stencil. Once thestencil is ready for doing the necessary job the printing base isagainelevated` to position l5 (Fig. 1) by actuation ofv valve 3T, and. asheet is dra-wn Vfrom the feed stack at 9 onto said base and positioned?bythe projections 46'. The valve 39' isthen actuated andi the' printing'base quickly carries the sheet to the screen, whereupon the operator EmovesV the squeegee' across the screen, effecting a printing on thesheet on the printing base. The printingv base is then lowered toposition I`51 and operator i2 quickly lifts4 it onto take-off' roller Ithat quickly deposits the same on conveyor llt that in turn carries thesheet to below the drying' lamps 4t..

Another sheet isf placed on the printing base and the'- operation isrepeated.

The operator 6 quickly manipulates the squeegee by himself. andtheoperator' I2l handles the feeding and removal' of they sheets byhimself. There is no swinging of a heavy printing frame and.s'qiie'egee, nor' is more than one man necessary for feeding' and'`removing sheets from the machine.

It is to be'. understood that the invention as described in' detail is'merely illustrative of the preferred' form of theinvention and` is notnecessarily restrictive thereof'.

We claim:

1. Screen printingV apparatus comprising a horizontal printing' frame?supporting a screen through which the printing medium is to be forcedfrom above, a fiat, substantially rectangular horizontal printing base;below said frame for supporting' the material to' receive the' saidmedium for making the desired imprint, axially extensible verticallydisposed telescopic posts supporting saidba'se at' points adjacent' itsfour corners-1 for vertical reciprocabl'e movement to and from saidframe, means for admitting uid undery pressure into said posts forextending the same" for causing said movement to saidframe and forexhaustingsaid iiuid for permitting collapse of said posts and movementof said base away from said frame, foot controlled' valve means belowsaid frame for controlling the flow of said iiuid intol and out ofsaidposts, and power means along one edge of said base for carrying sai'dmaterial away from said base when said p'osts are' collapsed and saidybase is spaced below said frame, the laterally projected area of thespacebe'tween said base and said frame along the edge of said baseopposite said one edge thereof being unobstructed for manualmanipulation of said material on said base by an operator positionedadjacent said one edge when said posts are collapsed. V

2. In screen printing apparatus that includes a rectangular, horizontalprinting frame carrying a stencil screen, tracks along two oppositesides of said frame, a squeegee having wheels rotatable on said tracksfor supporting said squeegee for movement over' the screenlongitudinallyV of said tracks, horizontal end members respectively eX-tending between the corresponding ends of said twoI opposite sides andadjacent the ends of said tracks for supporting the painting medium tobe drawn by said squeegee across said frame when said squeegee is movedfrom one end of said tracks to the other, a pair ofcorrespondinglyshaped elements respectively positioned adjacent corresponding endsl oisaid tracks and projecting above the latter for engaging the wheels ofvthe -squeegee and elevating the latter upon said wheels going over saidelements said elements being adjacent said end members whereby saidsqueegee will be elevated to pass over said medium after the latter isdrawn onto said end members, means yieldably supporting said elements inelevated position, stop means for holding said elements elevated againstdownward movement for so elevating said squeegee when the latter ismoved 01T said screen in direction away from the latter and onto saidelements, said elements being movable downwardly away from said stopmeans and against the yieldable resistance of said means under theweight of said squeegee upon reverse movement of said squeegee indirection toward said screen whereby said squeegee will engage saidmedium on said reverse movement for drawing the same over said screen.

WALLACE M. REEMELIN. ROGER W. OLMSTED.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,556,998 Katcher Oct. 13, 19251,843,116 Aldcroftt Feb. 2, 1932 1,922,341 Aldcroftt A1115;w 15, 19331,922,710 Owens Aug. 15, 1933 2,014,373 Brickell Sept. 17, 19352,039,909 Kem et al. May 5, 1936 2,061,679 Simonton Nov. 24, 19362,321,134 Fleisher et al. June 8, 1943

